🎞️ Video Processing

PixWit's video capabilities are split across two windows: Edit Audio/Video handles trimming, compression, speed adjustment, format conversion, dubbing, and audio splitting for videos and audio; opening a .gif / .apng file enters the Edit GIF Animation window, which handles animation trimming, speed adjustment, resizing, and frame editing.

Opening a Video

Supported Formats

Type	Formats
Video	mp4, avi, mov, mkv, flv, wmv, webm, m4v
Audio	mp3, wav, flac, aac, ogg, m4a, wma

Audio files can also be opened for processing, for example splitting them into segments with 🔪 Audio Split, or converting them to another audio format with 🔄 Convert.

Three Ways to Open

• Open from the main window: Click the Open Image button on the main window (the tooltip says "Open Image/Video"), then select a video or audio file in the file dialog.
• Drag and drop: Drag a video file directly onto the main window to open it.
• Edit after recording: Once a screen recording has been saved, click ✂️ Edit in the Recording Complete dialog that appears (the dialog also has ▶️ Open / 📂 Open Folder). Videos open the Edit Audio/Video window, and GIFs open the Edit GIF Animation window. For details on the recording flow, see Screen Recording.

Window Layout

Once opened, the Edit Audio/Video window contains 6 tabs:

Tab	Purpose
✂️ Trim	Trim the start and end, delete middle segments
🗜️ Compress	Reduce file size; change resolution and output format
⚡ Speed	0.5x to 3.0x playback speed
🔄 Convert	Convert to other video / audio formats, including GIF
🎙️ Dubbing	Record while the video plays and merge the new recording with the original video
🔪 Audio Split	Split audio into multiple files by segment duration

Behavior when closing the window

• After export completes, the window does not close automatically; you can continue working on the same file in other tabs.
• Closing the window exits it; there is no separate "Cancel" button in the interface.
• No unsaved-changes prompt appears when closing; adjustments that were not exported are not kept.

✂️ Trim

Timeline Controls

Action	Effect
Ctrl + mouse wheel	Zoom the timeline, from 10% to 1000%
Mouse wheel (when zoomed in)	Scroll horizontally
Drag the left or right handle	Adjust the start or end point (the handle can be grabbed within 16px on either side of its center)
Drag inside the selection	Move the whole selection
Double-click inside the selection	Play from that point to the end of the selection

The selection must be at least 0.5 seconds long.

Keyboard Fine-Tuning (Two Sets)

Keyboard fine-tuning comes in two sets; which set is active depends on whether the timeline has focus (if you have clicked the timeline, the first set is active):

When the timeline has focus	Function
← / →	Start point ∓0.1 seconds (Shift for 1 second)
↑ / ↓	End point ±0.1 seconds (Shift for 1 second)
Ctrl + arrow keys	Move the whole selection
, / .	Move the preview position by 0.1 seconds (without changing the selection)
Ctrl + mouse wheel	Zoom the timeline

When the timeline does not have focus	Function
← / →	Start point ∓0.1 seconds (Ctrl for 0.5 seconds)
↑ / ↓	End point ±0.1 seconds (Ctrl for 0.5 seconds)
Ctrl+Enter	Perform the trim
Esc	Exit full screen if in full screen; otherwise close the window

Mnemonic

When the timeline has focus, use Shift to move by 1 second; outside the timeline, use Ctrl to move by 0.5 seconds. To export directly from anywhere, press Ctrl+Enter.

Preview and Validation

• Click Play Selection to preview the selected content; during playback the button changes to Stop Playing.
• If the selection is shorter than 0.5 seconds, the app shows "Selected range too short, at least 0.5 seconds required".

Deleting Middle Segments

Use the ✂️ Delete Middle Segment group to manage the ranges you want to remove:

Button	Action
➕ Add	Add the current selection to the deletion list
➖ Remove	Remove the selected item from the deletion list
🗑️ Clear All	Clear the entire deletion list

When adding, the app validates that: start must be less than end, each segment must be at least 0.1 seconds, and ranges cannot overlap.

📷 Image placeholder (Figure 1)

Video trim timeline — shows the left and right handles, the selection, the delete-middle-segments list, and the export button at the bottom reading Trim... To add the image: place the file at docs/public/images/video-trim-timeline.webp, then delete this tip block and uncomment the next line.

Exporting the Trim

• The export button at the bottom actually reads Trim....
• Single-segment trim uses lossless copy (no re-encoding, so it is fast).
• Multi-segment trim (deleting middle segments) extracts the segments first and then merges them, showing "Extracting segment N/M..." and "Merging segments..." along the way.
• When finished, the app shows "✅ Trim Saved".

Default file names:

Scenario	Default file name
Single-segment trim	<original name>_trim_<start>-<end>_<timestamp>.<extension>
Multi-segment trim	<original name>_multiCut_<timestamp>.<extension>

🗜️ Compress

Setting	Options
Compression Quality	High Quality (CRF 23, ~30% compression) / Balanced Quality (CRF 28, ~50% compression) (default) / High Compression (CRF 32, ~70% compression)
Output Resolution	Keep Original Resolution (default) / 480p / 720p / 1080p / 4K
Output Format	MP4 (Recommended) (default) / AVI / MOV / MKV

Steps:

1. Open a video and switch to the 🗜️ Compress tab.
2. Choose the compression quality, output resolution, and output format.
3. Click Export Compressed Video; the progress dialog shows the percentage and the processed duration / total duration.
4. When finished, it shows the original size, compressed size, and compression ratio.

Default file name: <original name>_compressed_<original video timestamp>.<format>.

Video compression has only one entry point

Compression is available only through Edit Audio/Video → 🗜️ Compress; there is no separate menu item or keyboard shortcut.

📷 Image placeholder (Figure 2)

Video compression page — shows the three compression quality levels, output resolution, output format, and the Export Compressed Video button To add the image: place the file at docs/public/images/video-compress.webp, then delete this tip block and uncomment the next line.

⚡ Speed

Playback Speed	Description
0.5x Speed	Slow
0.75x Speed	Slightly slow
1.0x Speed	Normal (default)
1.5x Speed	Slightly fast
2.0x Speed	Fast
3.0x Speed	Ultra-fast

The app shows the tip "Speed is adjusted by changing the frame interval; the frame content is not modified". We recommend clicking Preview to check the result first, then Apply Speed to export.

🔄 Convert

Choose the target format, then click Export Converted File.

When converting to GIF, an extra 🎨 GIF Settings section appears:

Setting	Options
Frame Rate	10 FPS (Small File) / 15 FPS (Recommended) (default) / 20 FPS (Smooth) / 30 FPS (High Quality)
Size	Original Size / 720p / 480p (default) / 360p

On-screen tip text:

💡 Tip: GIF files are large, consider lowering the frame rate and resolution. Recommended for short videos (<10s).

Audio formats (MP3 / WAV / FLAC / AAC / OGG) are converted here as well: open an audio file and switch to the 🔄 Convert tab.

Video to GIF or GIF animation editing?

Here, Convert → GIF means converting a video into a GIF; opening an existing .gif / .apng file enters a different window — "Editing GIF Animations" — and the two are not the same feature.

📷 Image placeholder (Figure 3)

GIF settings under Convert — shows the target format selection, the frame rate and size dropdowns in 🎨 GIF Settings, and the file-size tip line To add the image: place the file at docs/public/images/video-gif-settings.webp, then delete this tip block and uncomment the next line.

🎙️ Dubbing

• ⚙️ Dubbing Settings contains four groups: 🎤 Recording Device, 🔊 Monitor, ⚙️ Mode, and 📊 Volume (the original audio and the recording can be adjusted separately).
• When Mute playback during dubbing (prevent echo) is checked, the video plays muted during dubbing, so the microphone does not also pick up sound from the speakers.
• Click Start Dubbing to record while the video plays; when finished, it is saved as a dubbed video, and the app merges the new recording with the original video.
• Examples of failure messages: No microphone device detected / Microphone device unavailable / Please select a microphone device / FFmpeg not found.

🔪 Audio Split

• ✂️ Split Settings contains Segment Duration and Output Format (Keep Original Format (default) / 🎵 MP3 / 🎼 WAV / 🎧 FLAC / 🔊 AAC / 🎶 OGG).
• Click Start Splitting to split the audio into multiple files at the set duration.
• Progress message: "Splitting audio... Will generate N files"; completion message: "🎉 Audio splitting complete!".
• Invalid parameters produce: "Split duration must be greater than 0 seconds!" or "Cannot get audio duration, please check if file is valid!".

Editing GIF Animations

This is not the same feature as Convert → GIF: that converts a video into a GIF, while here you edit an existing .gif / .apng file.

Opening a .gif / .apng file enters the Edit GIF Animation window, which has 4 tabs: Crop / Speed / Resize / Frame Editing.

• Crop / Speed / Resize: These three pages are similar to the video pages, and each has Preview plus a corresponding apply button (Apply Crop, Apply Speed, Apply Size).

• Frame Editing page:

  • The frame list shows thumbnails with #frame number delay ms;
  • The info bar shows "N frames total (M selected) | Total duration: ...";
  • Supports click to select, Ctrl multi-select, and Shift range select;
  • Delete deletes the selected frames;
  • Drag thumbnails to reorder frames;
  • Detect Duplicates: finds adjacent duplicate frames, with an adjustable threshold; after confirmation, deletes them in a batch.

• Original tip line on the Frame Editing page:

  Tip: Click a frame to select it (Ctrl for multi-select, Shift for range select) | Delete to remove | click "Apply Frame Edits" to save

Output and closing

• Only .gif can be output.
• Clicking Apply Crop, Apply Speed, Apply Size, or Apply Frame Edits on each page saves and closes the window.
• Closing the window discards unapplied changes.

📷 Image placeholder (Figure 4)

GIF Frame Editing page — shows the frame thumbnail list, #frame number delay ms, Ctrl multi-select and Shift range select, and duplicate detection To add the image: place the file at docs/public/images/video-gif-frame-edit.webp, then delete this tip block and uncomment the next line.

Shortcut Summary

Video trimming has two keyboard sets, and which set is active depends on whether the timeline has focus. See "Keyboard Fine-Tuning (Two Sets)" above for the complete comparison:

• Timeline has focus: ← / → start point ∓0.1 seconds, ↑ / ↓ end point ±0.1 seconds (Shift for 1 second each); Ctrl + arrow keys moves the whole selection; , / . move the preview position by 0.1 seconds; Ctrl + mouse wheel zooms the timeline.
• Timeline does not have focus: ← / → start point ∓0.1 seconds, ↑ / ↓ end point ±0.1 seconds (Ctrl for 0.5 seconds each); Ctrl+Enter performs the trim; Esc exits full screen if in full screen, otherwise closes the window.

GIF editing window:

Shortcut	Function
Delete	Delete selected frames
Ctrl+A	Select all frames on the Frame Editing page

Related Reading

• Screen Recording — the Recording Complete dialog and the ✂️ Edit entry after recording
• Keyboard Shortcuts — the complete key reference for video trimming and GIF editing
• Image Viewing and Editing (Chinese) — image cropping, format conversion, and printing (all image processing unrelated to video is covered here)